1. Field of the Invention
The present invention relates to a synchronous motor, and more particularly to a rotor of a synchronous motor and a method for manufacturing the same.
2. Description of the Related Art
A synchronous motor is a kind of alternate current motor. It has a stabilized rotating characteristic by being synchronized with an input frequency. It also can change a rotation frequency of the motor by changing a power frequency.
FIG. 1 is a longitudinal sectional view of a conventional rotor of a synchronous motor. Referring to FIG. 1, the rotor 20 includes an iron core 22 and an aluminum bar 21 passing through the iron core 22 permitting an induced current to flow easily from a stator (not shown).
The iron core 22 is made of a plurality of laminated thin iron sheets 10. One of the thin iron sheets 10 is shown in FIG. 2. A shaft hole 11 is formed at a center of the thin iron sheets 10 for receiving a rotating shaft (not shown). A plurality of aluminum-inserting holes 12 are radially formed around the outer circumference of the thin iron sheets 10.
The aluminum bar 21 is formed by ingoting aluminum material into the aluminum-embracing holes 12 at the iron core 22 formed of the laminated plurality of iron sheets 10.
When an induced current is transferred from a winding coil (not shown) to the stator (not shown) through the above construction, the rotor 20 receives the induced current from the aluminum bar 21 and rotates with a rotary shaft (not shown) connected thereto.
Furthermore, for the conventional rotor 20 of a synchronous motor, there is a limit to improve a rotating force of the motor only with the aluminum bar 21. Therefore, to improve the capability of the motor, one or more magnets (not shown) are disposed inside or on an outer circumference of the rotor 20. In addition, if the magnet is disposed inside of the rotor 20, the magnet should be settled using a metal can (not shown) and a rivet (not shown) for preventing the magnet from being separated while being rotated.
However, if the metal can and the rivet are used for settling the magnet, manufacturing procedure can be extended by many steps for producing the rotor 20, thus it can deteriorate the manufacturing capacity.
The present invention has been made to overcome the above-mentioned problems of the related art. Accordingly, it is an object of the present invention to provide a rotor of a synchronous motor and a method of manufacturing the same capable of shortening a manufacturing procedure and at the same time improving the capability of the motor.
The rotor of the synchronous motor according to the present invention to accomplish the above object, comprises a main core having a hole at a center for embracing a rotating shaft. The main core is formed from a plurality of laminated thin iron sheets that have a number of magnet holes and induced conductor holes radially disposed therein at a predetermined space differently from the hole. A predetermined number of magnets are inserted into the magnet holes of the main core. Supplementary cores, having a hole and an induced conductor hole at the corresponding place to the hole and the induced conductor hole of the main core, are disposed at the ends of the main core that the magnet is inserted therein. An induced conductor is formed by ingoting through the induced conductor holes of the main core and the same of the supplementary cores.
Also, the method of manufacturing the rotor of the synchronous motor of the present invention includes the steps of constructing a main core, having a hole at a center for embracing a rotating shaft, formed from a plurality of laminated thin iron sheets that a number of magnet holes and induced conductor holes radially disposed therein at a predetermined space differently from the hole; inserting magnets into the magnet holes of the main core; disposing a supplementary cores, having a hole and an induced conductor holes at the corresponding place to the hole and the induced conductor holes of the main core, at the ends of the main core; and ingoting an induced conductor through the induced conductor holes of the main core and the same of the supplementary cores.